• Asian-Australasian Journal of Animal Sciences
• /
• 제21권6호
• /
• pp.838-844
• /
• 2008

This experiment was conducted to evaluate the effect of supplementing a fat diet with selenium (Se) and vitamin E on performance of cows, blood antioxidant status and milk fatty acid composition. Sixty-three lactating Holstein cows were randomly divided into seven groups of nine cows each and each group was fed one of the following diets: i) a basal diet (control); ii) a basal diet with 0.15 mg Se/kg DM (LSe); iii) a basal diet with 0.3 mg Se/kg DM (HSe); iv) a basal diet with 5,000 IU/cow d vitamin E (LVE); v) a basal diet with 10,000 IU/cow d vitamin E (HVE); vi) a basal diet with 0.15 mg Se/kg DM and 5,000 IU/cow d vitamin E (LSeVE); vii) a basal diet with 0.3 mg Se/kg DM and 10,000 IU/cow d vitamin E (HSeVE). Milk fat percentage and conjugated linoleic acid (CLA) yield in HVE and HSeVE diets increased (p<0.05) compared with the control diet. In milk fat, dietary supplementation of Se tended to increase the proportion of the sum of unsaturated fatty acids (UFA) and significantly decreased (p<0.05) the proportion of the sum of saturated fatty acids (SFA). In addition, compared with the control, thiobarbituric acid reactive substances (TBARS) content was lower and glutathione peroxidase (GSH-Px) was higher when fat diets were supplemented with Se. Our data showed that supplementation with Se and/or VE improved these nutrients in blood and milk. The results indicated that fat diets supplemented with Se improved both antioxidant status in blood and fatty acids in milk fat, and fat diets supplemented with vitamin E alleviated milk fat depression. Therefore, the combination of Se and vitamin E caused synergistic effects on the nutritional quality of milk fat and performance of cows fed a fat diet.

• Asian-Australasian Journal of Animal Sciences
• /
• 제30권8호
• /
• pp.1105-1116
• /
• 2017

Objective: A meta-analysis was conducted to evaluate the effects of supplemental fat containing saturated free fatty acids (FA) on milk performance of Holstein dairy cows. Methods: A database was developed from 21 studies published between 1991 and 2016 that included 502 dairy cows and a total of 29 to 30 comparisons between dietary treatment and control without fat supplementation. Only saturated free FA (>80% of total FA) was considered as the supplemental fat. Concentration of the supplemental fat was not higher than 3.5% of diet dry matter (DM). Dairy cows were offered total mixed ration, and fed individually. Statistical analysis was conducted using random- or mixed-effects models with Metafor package in R. Results: Sub-group analysis showed that there were no differences in studies between randomized block design and Latin square/crossover design for dry matter intake (DMI) and milk production responses to the supplemental fat (all response variables, $p{\geq}0.344$). The supplemental fat across all studies improved milk yield, milk fat concentration and yield, and milk protein yield by 1.684 kg/d (p<0.001), 0.095 percent unit (p = 0.003), 0.072 kg/d (p<0.001), and 0.036 kg/d (p<0.001), respectively, but tended to decrease milk protein concentration (mean difference = -0.022 percent unit; p = 0.063) while DMI (mean difference = 0.061 kg/d; p = 0.768) remained unchanged. The assessment of heterogeneity suggested that no substantial heterogeneity occurred among all studies for DMI and milk production responses to the supplemental fat (all response variables, $I^2{\leq}24.1%$; $p{\geq}0.166$). Conclusion: The effects of saturated free FA were quantitatively evaluated. Higher milk production and yields of milk fat and protein, with DMI remaining unchanged, indicated that saturated free FA, supplemented at ${\leq}3.5%$ dietary DM from commercially available fat sources, likely improved the efficiency of milk production. Nevertheless, more studies are needed to assess the variation of production responses to different saturated free FA, either C16:0 or C18:0 alone, or in combination with potentially optimal ratio, when supplemented in dairy cow diets.

• Journal of Dairy Science and Biotechnology
• /
• 제32권2호
• /
• pp.63-70
• /
• 2014

Automatic milking systems (AMS) have been increasingly introduced to Korean dairy farms. However, in comparison with conventional milking systems (CMS), some negative changes in milk quality are being observed. The use of AMS leads to an increase in milking frequency, which in turn might result in higher physical stress on the milk, possibly causing changes in the milk fat globule (MFG) membrane. Therefore, the purpose of this study was to examine the effect of the different milking systems on the milk quality, with a focus on milk fat properties. At the same time, we studied the effect of feeding the dairy cows with protected fat. Raw milk samples were taken monthly from individual cows as well as from bulk tanks at four AMS and four CMS dairy farms. We measured quality-related parameters such as MFG size distribution, free fatty acid content and composition, and acid values. Although most results showed no significant differences with regard to the milking system, we found a relatively high positive correlation between MFG size and milk fat content. Moreover, larger MFG size was observed in the milk when cows had been fed protected fat. The significantly higher (P< 0.05) free fatty acid content of milk observed under this experimental condition could be attributed to higher milking frequency as a result of using AMS.

• 한국환경보건학회지
• /
• 제30권1호
• /
• pp.29-40
• /
• 2004

This study was performed to investigate and assess the composition of mineral and macronutrient contents in Korean cow′s milk.48 individual farm raw milk, 10 plant raw milk and 29 market milk were collected from June to August in 2003. The minerals such as calcium(Ca), potassium(K), magnesium(Mg), sodium(Na), zinc(Zn), iron(Fe) and phosphorus(P) were determined by using atomic absorption spectrometer(AAS). The macronutrients such as fat, protein and lactose were tested by using IR spectrometer. The obtained analytical results of minerals(mg/100 g) and rnaetronutrients (％) are as follows：1. In case of raw cow′s milk ； Ca 113.56, K 144.09, Mg 10.86, Na 42.53, Zn 0.42, Fe 0.030, p 113.32, fat 3.85, protein 3.08, lactose 4.80,2. In case of market cow′s milk ; Ca 103.04, K 142.46, Mg 10.27, Na 43.21, Zn 0.40, Fe 0.034. p 97.30, fat 3.78, protein 3.05, lactose 4.70,3. In case of fortified market cow′s milk ; Ca 165.40, K 145.79, Mg 10.57. Na 42.55, Zn 0.57, Fe 0.414, p 94.68, fat 3.74, protein 3.08, lactose 4.68,4. In case of processed market cow′s milk ; Ca 134.72, K 142.74, Mg 10.33, Na 45.07, Zn 0.50, Fe 0.650, p 92.48, fat 3.72, protein 3.07, lactose 4.74. According to the group of market milk(milk, fortified market row′s milk, processed market cow′s milk), the mean concentration of Ca and Fe were significantly higher in fortified and processed milk than milk(p<0.05). There were no significant differences in macronutrient(fat, protein, lactose) and mineral contents between pasteurized milk and UHT(ultra high temperature) treated milk($\alpha$=0.05). The labeled "Nutritional Facts" of market milk were satisfied with "Labeling Standards for Livestock Products of Korea". The measured mean concentrations of Ca, Fe, Zn were generally higher than lower limit of labeled value(above 80% of labeled value). The mean concentration of sodium was lower than upper limit of labeled value(below 120％ of labeled value).

• 한국축산식품학회:학술대회논문집
• /
• 한국축산식품학회 2004년도 제34차 추계 국제 학술대회
• /
• pp.218-222
• /
• 2004

Low-fat (< 3%)/salt(< 1%) sausages were manufactured with two levels (1, 2%) of milk proteins(whey protein and sodium caseinate) to compensate for the textural problems due to reduced fat and salt(%). The addition of two levels of milk proteins into these meat products did not affect the most physicochemical and textural properties. As compared to regular-fat counterpart, higher expressible moisture of low-fat/salt sausages were observed. In addition, low-fat/salt sausages containing more than 2% of milk proteins reduced the textural hardness and gumminess, resulting in significantly lower these values, as compared to regular-fat counterparts. These results indicated that the low-fat/salt sausages were successfully manufactured with the addition of these milk proteins at the lower than 1% to improve the textural difference, however further research will be performed to improve the water holding capacity in these products.

• Asian-Australasian Journal of Animal Sciences
• /
• 제13권2호
• /
• pp.182-187
• /
• 2000

Forty-two Holstein cows (21 multiparous) were assigned by calving date and parity to three dietary sequences to evaluate the effect of time of initiating fat supplementation to diets on lactation and reproductive performance. The dietary sequences were: 1) control, no supplemental fat from 1 to 98 days in milk (DIM) ; 2) control diet from 1 to 28 DIM then 3% supplemental fat (calcium salts of long-chain fatty acids) from 29 to 98 DIM; or 3) 3% supplemental fat from 1 to 98 DIM. Feeding supplemental fat did not enhance mean milk and 4% fat corrected milk (FCM) yields, but efficiency of FCM production was higher for cows fed supplemental fat. Milk fat percentage was unchanged whereas milk protein percentage was depressed with fat supplementation. Feeding supplemental fat reduced DMI and energy balance but there were no differences among treatments on time to resumption of ovarian cyclicity or conception rate to first service. Concentrations of progesterone during the first two ovulatory cycles tended to be greater in the fat-supplemented groups. Feeding supplemental fat starting at either parturition or 29 DIM increased efficiency of FCM production, but did not greatly enhance reproductive performance.

• Animal Bioscience
• /
• 제35권3호
• /
• pp.377-384
• /
• 2022

Objective: This study was conducted to estimate multi-trait genetic parameters for somatic cell score (SCS), milk yield and type traits in Nigerian Dwarf (ND) goats from the United States. Methods: Data from 1,041 ND goats in the United States with kiddings in 95 herds were used to estimate multi-trait genetic parameters for SCS, milk (MILK), fat (FAT), and protein (PROT) yields, and 14 type traits. An 18-trait mixed linear animal model for lactation mean SCS (Log₂), MILK, FAT, PROT, and 14 type traits was applied. A factor analytic approach (FA1) in ASReml software was used to obtain convergence. Results: Averages for SCS were low (2.85±1.29 Log₂), and were 314±110.6, 20.9±7.4, and 14±4.9 kg, respectively, for MILK, FAT, and PROT. Heritabilities for SCS, MILK, FAT, and PROT were 0.32, 0.16, 0.16, and 0.10, respectively. The highest heritabilities for type traits were for stature (0.72), teat diameter (0.49), and rump width (0.48), and the lowest estimates were for dairyness (0.003) and medial suspensory ligament (0.03). Genetic correlations of SCS with MILK, FAT, and PROT were positive but low (0.25, 0.18, and 0.23, respectively). Genetic and phenotypic correlations between MILK, FAT, and PROT were high and positive (≥0.66). Absolute values of genetic correlations involving SCS with type traits were generally low or no different from zero. Most of the phenotypic correlations involving SCS with type traits were low. No serious unfavorable genetic correlations between milk yield traits and SCS or between milk yield traits or SCS and type traits were found. Conclusion: Genetic variation exists in the ND breed for most studied traits. The development of selection programs based on these estimates may help accelerate favorable multi-trait genetic changes in this breed.

• Asian-Australasian Journal of Animal Sciences
• /
• 제20권10호
• /
• pp.1525-1538
• /
• 2007

Because of the increasing evidence of potential benefits of conjugated linoleic acid (CLA) on human health, there is a need to investigate its status in commercial dairies and develop feeding strategies to enhance the content and supply of CLA in milk and milk products. A two-year experiment was conducted to study the status of milk fat c-9, t-11 CLA on four selected commercial dairy farms in Utah (two) and Idaho (two), USA. Farms A and C grazed cows on pasture and supplemented with 7.0 kg/cow per day of their respective grain mixes during summer, while conserved forage and grain mix was fed during winter. Farm B fed a total mixed diet all year, with 10% of diet dry matter as fresh cut pasture during summer. Farm D had 1/3 of its cows grazed on pasture and supplemented with a total mixed diet during summer, while the rest were fed a total mixed diet. All cows in Farm D were fed a total mixed diet during winter. Farms A, B, C, and D had on average 80, 400, 150, and 500 milking cows, respectively, with Holstein or its crosses as the major breed. On a year-round basis, Farms A and C produced milk with 60% or more milk fat c-9, t-11 CLA and transvaccenic acid (TVA) contents than Farm B. Similarly, Farm D produced 30% or more c-9, t-11 CLA and TVA in milk than Farm B. Milk fat content of CLA and TVA was 150-200% more during summer compared with winter. Individual cows varied from 0.16 to 2.22% in milk fat c-9, t-11 CLA contents and 89% of the cows had c-9, t-11 CLA contents between 0.3 and 1.0% of milk fat. Individual cow variation was larger on Farms A and C compared with Farm D, with least variation on Farm B. Variation was larger in summer than in winter. The bulk tank milk c-9, t-11 CLA content varied from 0.27 to 1.35% of milk fat. Cows on Farms A and C produced similar or higher amounts of milk fat c-9, t-11 CLA on a daily basis even though their milk yield was lowest among the dairies. Concentration and supplies of c-9, t-11 CLA and TVA were highest from June through September and lowest from February through April, which should be the months for targeting improvement in the content and supply of milk fat c-9, t-11 CLA and TVA.

• Asian-Australasian Journal of Animal Sciences
• /
• 제21권3호
• /
• pp.376-385
• /
• 2008

Twenty lactating crossbred cows yielding 10 to 15 litres of milk daily during mid lactation were selected and divided into four groups of five animals to assess the effect of feeding calcium soaps of palm oil fatty acids (bypass fat) on milk yield, milk composition and nutrient utilization in lactating crossbred cows. The animals in groups 1 (control), 2, 3 and 4 were fed concentrate mixture containing 0 (no bypass fat), 2, 4 and 6% bypass fat, respectively. The average daily dry matter consumption in the various groups ranged from 13.1 to 13.6 kg and showed no significant difference among treatment groups. There was no significant difference among different groups in digestibility of DM, OM, CP and CF, however, ether extract digestibility in cows of groups 2 and 4 was significantly (p<0.05) higher than the control group. The average milk yields of the cows in group 3 (4% bypass fat) showed a significantly (p<0.05) higher value than cows of groups 1 and 2. Similarly, a significant (p<0.05) increase in fat yield, 4% FCM yield and SNF yield was observed for the cows in group 3 (4% bypass fat). The milk composition in terms of total solids, fat, lactose, protein, solids-not-fat and ash percentage showed a varying response and bypass fat feeding did not have any effect on milk composition of cows in different groups. The gross and net energetic efficiency of milk production ranged from 23.6 to 27.5% and 37.1 to 44.4%, respectively, and showed no significant difference among different treatment groups. The gross and net efficiency of nitrogen utilization for milk production ranged from 24.0 to 28.7% and 37.2 to 43.5%, respectively, and no significant difference was noted among different treatment groups. The supplementation with calcium salts of palm oil fatty acid reduced the proportion of caproic, caprylic and capric acids and significantly (p<0.01) increased the concentration of palmitic, oleic, stearic, linoleic and linolenic acids in milk fat with increase in level of bypass fat supplementation. It was concluded that incorporation of calcium salts of palm oil fatty acids at a 4% level in the concentrate mixture of lactating crossbred cows improved the milk production and milk quality in terms of polyunsaturated fatty acids without affecting the digestibility of nutrients.

• Journal of Dairy Science and Biotechnology
• /
• 제33권3호
• /
• pp.209-214
• /
• 2015

AMS와 CMS 및 보호지방의 급여 여부가 우유 성분과 유지방 특성에 미치는 영향을 조사하기 위하여 본 연구를 실시하였다. 착유방식과 보호지방 급여 여부에 따라 AMS 및 CMS 목장을 각 4개소씩 선정하여 월 1회 집합유 원유시료를 채취하였으며, 총 5개월간 유성분, 유지방구(MFG) 크기, 지방산 및 유리지방산 조성을 분석하였다. 착유방식에 따른 일반 유성분, MFG 크기, 지방산 조성의 유의적 차이는 관찰되지 않았으나, AMS로 착유된 우유의 유리지방산 함량이 CMS로 착유된 우유에 비해 유의적으로(p<0.05) 높았으며, 이는 AMS 의 착유 횟수가 CMS에 비해 더 많았기 때문인 것으로 판단된다. 보호지방을 급여한 농장의 우유를 비급여 농장과 비교하였을 때 유성분에는 차이가 없었으나 장쇄지방산(LCFA) 함량이 더 높은 것으로 나타났으며, 유지방구의 크기 또한 증가하는 경향을 보였는데 이는 급여한 보호지방의 주요지방산인 LCFA가 유지방으로 전이되었기 때문으로 해석된다. 또한 공시한 모든 AMS 목장에서 원유의 산패문제는 발생하지 않았는데, 유리지방산 함량이 CMS에 비해 유의적으로 높았지만 산패를 일으킬 정도로 높은 수준은 아니었던 것으로 판단된다. 이상의 결과를 바탕으로 할 때 AMS는 유성분 및 유지방 특성의 측면에서 CMS 대비 주목할 만한 차이를 보이지 않았으며 보호지방의 급여는 유지방구 크기 및 장쇄지방산 농도에 영향을 미치므로 향후 목장형 유가공을 실시할 경우 이를 응용할 여지가 있을 것으로 사료된다.